Nuclear analytical techniques (PIXE, KBS and ERDA) have been applied to inv
estigate diffusion processes in polymer light-emitting diodes (PLEDs), empl
oying a 30 MeV AVF cyclotron. The techniques prove to be useful in identify
ing the origin of the diffusion process and the nature of:molecules transpo
rted from the hole injecting ITO electrode into the polymer layer.